Flask retainer



A. M. ASHMAN FLASK RETAINER June 8, 1948.

Filed March 23 1946 INVENTOR, 7124724. BY

A T TURN EY.

Patented June 8 1943 UNITED STATES PATENT OFFICE 2,442,885 V FLASKRETAINER Albert M. Ashman, Seal Beach, Calif.

Application March 23, 1946, Serial No. 656,695

1 Claim.

The present invention relates to flask retainers of a type which permita flask to be subjected to pressure, such as hydraulic pressure, andthereafter to hold the flask and any molding material in the flask underpressure.

Primarily, the flask retainer of the present invention is utilized inconnection with the forming of dentures and prosthetic devices used indentistry. By way of example, inlays, crowns, bridges and the like maybe made very satisfactorily from plastic material such as Crystolex,which is an acrylic resin. Other materials may be used, such asphenol-formaldehyde resin, as well as mixed acrylic resins and vinylresin. These plastics are capable of combining natural color eliects andtranslucency with excellent color stability. The acrylic resins havegood aging properties in the presence of oral fluids and when exposed tothe air, as well as having resistance to warping, lightness in weightand comfort in use, with resistance to bacterial growth.

The device of the present invention facilitates the molding of denturesand prosthetic devices used in dentistry.

An object of the invention is the provision of a flask retainer which issimple of construction, positive in operation, performs the functionrequired of it in an efficient manner and is superior to devices nowknown to the inventor.

In the drawing:

Fig. 1 is a fragmentary partially sectional elevation of the invention;

Fig. 2 is a fragmentary partially sectional side elevation of theinvention;

Fig. 3 is a fragmentary sectional View on the line 3-3 of Fig. 1; and

Fig. 4 is a perspective View of one of the elements of the invention.

Referring now with particularity to the drawmg:

The improved flask retainer is designated as an entirety by I, and. thesame includes a base 2, formed with a pair of screwthreaded studs 3 and4 adapted to receive and retain the screw ends of posts 5 and 6, whichposts are positioned substantially vertically on the base and spacedapart a desired distance. Each post may be substantially circular incross section and longitudinally flattened at 1, as illustrated in Fig.3. A top plate 8 is formed with a transverse enlargement 9, which iseither integral with the plate or formed separately therefrom, and whichenlargement and plate are transversely bored at It and H to permitpassage therethrough of the said posts 5 and 6. Ends of the enlargement9 are screwthread- 2 edly bored as illustrated at l2 and I3 to receivewing-type screws designated generally as M. Heads l5 are provided forthe posts 5 and 6 to limit upward movement of the top plate.

The operation, uses and advantages of the invention are as follows:

At [6 I have provided a flask which is adapted to hold a plaster such asHydro-eel, a product of the U. S. Gypsum Corporation. This plasterconstitutes what may be termed an investment material and is formedaround the pattern. This pattern is usually made of wax, and the Wax ismelted from the mold so that further operation may proceed. It isnecessary in the practice that the wax material be entirely removed, andthis may be done in the usual way, such as by heat and the use of carbontetrachloride. The plastic is next prepared, and if an acrylic powder isto be used, the monomeric substance is mixed with the polymer so as toform a puttylike mass which may be forced intothe mold cavity. Thissubstance is left extruding beyond the plaster in the flask. The flaskis then placed on the base 2 between the posts 5 and 6, as shown in Fig.1, the top member 8 is brought into contact with the top of the flaskand specifically the plastic substance, whereupon a ram [1 of a press,such as a hydraulic press, is brought into engagement with the top ofthe enlargement 9 and the plastic substance is subjected to pressure.The wing screws have been loosened prior to the application of pressureagainst the top member, and after the desired pressure has been appliedthe wing screws are tightened so that the screws engage the flattenedlongitudinal edge I of each post to lock the top against movement. Thedevice as an entirety is then placed in a hot water bath for a suitablelength of time to polymerize the plastic and form the molded article.

The pressing of the plastic into the mold under pressure and maintainingthe said pressure prevents vaporization of the plastic duringpolymerization, with the result that the molded plastic article is notporous, bubbles are not present and a smooth homogeneous structureresults which does not require further polishing. It is perhapsunnecessary to state that the plaster is broken from the plastic topermit access to the molded article.

I claim:

1. A flask retainer, including a base, a pair of spaced apart uprightposts secured to said base, each post formed with a longitudinallyflattened area, a top comprising a flat plate provided with a centralenlargement transversely extending between sides thereof, the said plateand enlargement being formed with a. pair of transverse bores to permitpassage of the posts therethrough, and screw means adJustably carried.at both ends of the enlargement for engagement with the flattened areasof said posts to lock the said top in adjusted position thereto.

ALBERT M. ASHMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

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